The Three Laws of Planetary Motion

Johannes Kepler's Three Laws of Planetary Motion describe how planets move around the Sun. First, planets travel in elliptical (oval-shaped) orbits, with the Sun at one focus. Second, a planet’s speed varies; it moves faster when closer to the Sun and slower when farther away, sweeping equal areas in equal times. Third, the time a planet takes to orbit the Sun (its year) relates to its average distance; specifically, the square of its orbital period is proportional to the cube of its average distance from the Sun. These laws reveal the predictable, gravitationally influenced patterns of planetary movement.